A representative conventional weatherstrip obtained by molding in a mold (hereinafter simply referred to as a "molded weatherstrip") that is applied to the corner of an automotive door is shown in FIG. 5 through FIG. 9, while the details such as the curvature radius, total length, method of fixing, and the like somewhat vary depending on whether the door is of a sash type or a panel type. To take an instance, application of the panel type to the upper, center-pillar side corner of a front door is illustrated.
FIG. 5 is a plan view of a front door FR of panel type, seen from the outside of the car. The upper part of the front door FR above the belt line J--J is also composed of an outer panel and an inner panel shaped by press working integrally with the main part of the door. Retainers RT for fixing a weatherstrip, which are indicated by dotted line in FIG. 5, come to an end in front of the upper, center-pillar side corner so that the weatherstrip is not fixed at this corner (hereinafter called "unfixed area").
FIG. 6 is a cross sectional view of the front door FR, taken along the line A--A shown in FIG. 5. An inner panel IP is welded to an outer panel OP. A retainer RT is welded to the inner panel IP along the periphery thereof above the belt line, into which a relatively long extrusion-molded weatherstrip (hereinafter referred to as an "extruded weatherstrip") is fitted. A sash GS for glass run is welded to the outer panel OP along the periphery thereof above the belt line which defines an opening portion for a glass window.
Shaped by press working, the front door FR has a considerably larger curvature radius at the corner than that of a sash type door. Therefore, the unfixed area inclusive of a straight portion is longer than that of a sash door. In some designs a retainer RT is not at all provided on the center pillar side and, instead, other means, such as a clip, is used for fixing the weatherstrip.
Even in a sash door that could be designed to have a complicated bend with a relatively small curvature at the corner, an unfixed area is unavoidably produced at the corner.
Hence, various manipulations have ever been proposed for fixing a molded weatherstrip.
As is apparent from FIGS. 7 to 9, an extruded weatherstrip 1 and a molded weatherstrip 10 have conventionally been connected at a joint portion WL.sub.1 as follows. A mold (not shown) containing a core CR.sub.1 shown in FIG. 9 is used. One end of the previously extruded weatherstrip 1 is inserted to the end of the mold to be fitted with the mold via the core CR.sub.1. A tabular insert panel INP.sub.1 is then set in the mold at the position corresponding to a base 11 of a weatherstrip 10. A molding material is inserted to be molded using the thus prepared mold to obtain a molded weatherstrip 10 having a desired shape and, at the same time, to join the weatherstrips 1 and 10 into one integral body.
The extruded weatherstrip 1 and the molded weatherstrip 10 thus joined have almost the same cross sectional shape except for their bases. The extruded weatherstrip 1 comprises: a base 2 which has a relatively narrow hollow portion 3 and which is to be fixed into the retainer RT; a hollow tubular seal 4 which protrudes from the base 2 toward the body panel; a first seal lip 5 which extends from the side of the hollow tubular seal 4 facing inside the car toward inside the car; and a second seal lip 6 which extends from the side of the hollow tubular seal 4 facing outside the car toward outside the car and which is to seal the back side the panel door.
On the other hand, the molded weatherstrip 10 comprises: a base 11 which completely encloses the tabular insert panel INP.sub.1 and which has an almost flat shape so that it may be easily removed from the mold; a hollow tubular seal 12 protruding from the base 11 toward the body panel; a first seal lip 13 extending from the hollow seal 12 toward inside the car; and a second seal lip 14 extending from the hollow seal 12 toward outside the car and sealing the back side of the panel door.
The core CR.sub.1 has a subcore SCR that is fitted into the hollow portion 3. The root of the subcore SCR connecting to the main portion of the core CR.sub.1 has its rear side sloped. This slope gives a difference h in wall thickness of the base 11 of the molded weatherstrip 10 at the tip thereof as shown in FIG. 8. As a result, the base 11 of the molded weatherstrip 10 has a tapered end in the vicinity of the joint portion WL.sub.1. That is, the base 11 very near to the joint portion WL.sub.1 is thin-walled as compared with the thickness at the tip of the tabular insert panel INP.sub.1.
Because the tabular insert panel INP.sub.1 should extend to the position where the retainer RT exists so as to prevent penetration of water, the conventional molded weatherstrip 10 includes a long straight portion as well as a curved portion and therefore has a long overall length. Therefore, the molding material tends to reduce its flowability while flowing through such a long mold, resulting in deteriorated quality. An additional problem of the conventional weatherstrip is that the thin-walled portion of the base 11 in the vicinity of the joint portion WL.sub.1, which results from the level difference h at the rear of the subcore SCR, has caused reductions in joint strength and watertightness at that portion.